Do I need to drill a thumb hole in a bowling ball? I know there are weight issues will have to put a serious weight hole in the bottom heavy side to stay in USBC spec's but does it have to be a thumb hole?? My son throws with two fingers he is a full roller which we found out the hard way.. his fingers kept cracking to the point his ball was ruined this happened on three of his balls the pro shop guy would just say well um thats how he throws it..lol Well after drilling balls myself and learning the hobby/trade I now know he is a full roller and needed his balls drilled completely different..
My question is could I drill his fingers then add a weight hole without actually putting in a thumb hole? Thanks guys for the help.